Search results
Results from the WOW.Com Content Network
Historically, the mole was defined as the amount of substance in 12 grams of the carbon-12 isotope.As a consequence, the mass of one mole of a chemical compound, in grams, is numerically equal (for all practical purposes) to the mass of one molecule or formula unit of the compound, in daltons, and the molar mass of an isotope in grams per mole is approximately equal to the mass number ...
The mole is widely used in chemistry as a convenient way to express amounts of reactants and amounts of products of chemical reactions. For example, the chemical equation 2 H 2 + O 2 → 2 H 2 O can be interpreted to mean that for each 2 mol molecular hydrogen (H 2) and 1 mol molecular oxygen (O 2) that react, 2 mol of water (H 2 O) form.
Stoichiometry is not only used to balance chemical equations but also used in conversions, i.e., converting from grams to moles using molar mass as the conversion factor, or from grams to milliliters using density. For example, to find the amount of NaCl (sodium chloride) in 2.00 g, one would do the following:
The molar mass is defined as the mass of a given substance divided by the amount of the substance, and is expressed in grams per mol (g/mol). That makes the molar mass an average of many particles or molecules (potentially containing different isotopes), and the molecular mass the mass of one specific particle or molecule. The molar mass is ...
In chemistry, the molar mass (M) (sometimes called molecular weight or formula weight, but see related quantities for usage) of a chemical compound is defined as the ratio between the mass and the amount of substance (measured in moles) of any sample of the compound. [1] The molar mass is a bulk, not molecular, property of a substance.
By this definition, the number of equivalents of a given ion in a solution is equal to the number of moles of that ion multiplied by its valence. For example, consider a solution of 1 mole of NaCl and 1 mole of CaCl 2. The solution has 1 mole or 1 equiv Na +, 1 mole or 2 equiv Ca 2+, and 3 mole or 3 equiv Cl −.
The equivalent weight of an element is the mass which combines with or displaces 1.008 gram of hydrogen or 8.0 grams of oxygen or 35.5 grams of chlorine. The equivalent weight of an element is the mass of a mole of the element divided by the element's valence. That is, in grams, the atomic weight of the element divided by the usual valence. [2]
In chemistry, a mole map is a graphical representation of an algorithm that compares molar mass, number of particles per mole, and factors from balanced equations or other formulae. [1] They are often used in undergraduate-level chemistry courses as a tool to teach the basics of stoichiometry and unit conversion. [2] [3] [4]